Charmed Again 4.01 & 4.02
Phoebe and Piper struggle to come to terms with the death of their sister and the realization that the Power of Three no longer exists without her. When they discover the existence of their baby half-sister, Paige, Phoebe and Piper are hopeful that they can reconstitute the formidable triad of witches, but The Source has a 48-hour window to turn Paige evil forever.

Hell Hath No Fury 4.03
New to the witchy world of The Charmed Ones, Paige is learning to control her new telekinetic powers and steals the Book of Shadows from Phoebe and Piper to use the spells for personal gain. Meanwhile, Piper's inability to deal with her sister's recent death makes her vulnerable to the Furies, female demon vigilantes who lure her into their fold.

Size Matters 4.04
Phoebe and Piper don't take Paige seriously when she has a weird feeling about a creepy old house, landing Phoebe in the clutches of a hideous demon and shrunk to a powerless five inches tall. When Paige and Piper also walk into the demon's trap, his collection is complete.

Enter The Demon 4.05
Paige makes a major blunder when carelessly mixing potions for Piper while secretly wishing she could be in Phoebe's shoes training for combat, and ends up actually switching bodies with Phoebe. While the two sisters try to reverse the spell and struggle to harness each other's powers, they must battle a Zen Master's powerful disciple who has turned evil against his mentor and opened up a portal between two worlds.

A Knight To Remember 4.06
Paige's favorite childhood fairy tale suddenly becomes real, bringing her face-to-face with a past life as an Evil Enchantress from Medieval times and into the arms of a Knight in Shining Armor. Phoebe and Piper go back in time and end up trapped in the Dark Ages.

Brain Drain 4.07
Phoebe and Paige must work quickly before Piper is tricked into giving up all of their powers when The Source taps into her brain, altering her perception of reality and placing her in a mental institution.

Black As Cole 4.08
In the midst of mulling over his marriage proposal, Phoebe comes face-to-face with Cole's demonic past when a widow tracks him down seeking vengeance for her husband's murder. Meanwhile, Paige encourages Piper and Leo to test their readiness to become parents.

Muse To My Ears 4.09
Now that the Source is wounded, Cole worries that various forces of evil will target the Charmed Ones in order to prove themselves worthy of taking the Source's place. The girls soon learn that Cole's fears were justified when Devlin, a warlock, uses the Ring of Inspiration to capture muses and use their powers to inspire a faction of warlocks help him destroy the Charmed Ones and to overthrow The Source. Meanwhile, while still trying to adjust to his loss of his demonic powers, Cole buys a gun in order to help protect Phoebe.

A Paige From The Past 4.10
Piper and Phoebe learn that Paige still blames herself for the death of her parents and can't move on. Leo suggests that Paige use the skills of The Ghost of the Past to travel back in time to help her learn why her parents were really killed. While there Paige attempts use the opportunity to change the past and save her parents from their deadly car accident. Meanwhile, two ghosts possess Phoebe and Cole in order to complete some unfinished business that Piper and Darryl learn is to get married.

Trial By Magic 4.11
While serving on a jury in case of a stage magician accused of murdering his wife, Phoebe has a premonition that the defendant is not the real killer. Phoebe now realizes his claims to have had a premonition which allowed him to lead the police his wives' body was real and not just an ploy to get away with murder. Unable to convince her fellow jurors that the man was framed, she must prove that magic really exists in order to win them over. Piper becomes irritated when Paige invites her friend Glen to stay at the Manor while in town.

Lost And Bound 4.12
Paige brings Tyler, a runaway, to the Manor after witnessing him starting a fire with his mind. After Piper gains Tyler's trust, she learns that his foster parents were going to send him to a demonic academy that would normally train those with his magical gift to be body guards of the Source. Elsewhere while Cole tries to be more human and start a new job, Phoebe begins to turn into an old-fashion housewife after putting on her Grandmother's engagement ring.

Charmed And Dangerous 4.13
When The Source's Seer foresees the death of his master at the hands of the Charmed Ones The Source vows to unleash an ancient evil in an attempt to gain more power so he can destroy the Warren line forever! Meanwhile Paige must use magic to help cover up a womens bruises when she tries to gain custody of her son.

The Three Faces Of Phoebe 4.14
When Phoebe has second thoughts about marrying Cole, she turns to magic to help her decide. Her spell has some undesired effects when she summons her past younger self and her future older self to the present, neither being willing at first to help Phoebe with her problem. Meanwhile, Cole finds himself slowly being taken over by The Source, as old rival seeks to takes The Source's place in the underworld. Paige learns a recent spell gave her the edge over a colleague for a promotion.

Marry-Go-Round 4.15
Phoebe is hoping that everything will be perfect for her and Cole's wedding, but doesn't know that The Source has completely taken over the groom and is sabotaging the ceremony in order to orchestrate a demonic wedding which will allow their foretold son to be heir to the underworld. Cole's underhanded tactics include secretly sending a powerful demon to disrupt the wedding and planting the seeds of infighting among Phoebe and her sisters.

The Fifth Halliwheel 4.15
Paige feels like the 'fifth wheel' as Piper and Leo celebrate their first anniversary and newlyweds Cole and Phoebe paw at each other. Cole, however has other plans when he learns that he has to impregnate Phoebe within the next twenty-four hours in order to have a child that will turn out evil. Meanwhile, the girls encounter an innocent who was used by a Demonic Power Broker, to store a power, which could kill her if the girls can't get her the needed potion in time.